Vanadium acid oxalate and process of making same.



UNITED sTATEs PATENT OFFICE.

PAUL REHLANDER, 0F CHARLOTTENBURG, GERMANY, ASSIG'NOR T0 CHEMISCHEFABRIK .AUF ACTIEN (VORM. E. SCI-IERING), OF BERLIN, GERMANY.

VANADjIUM ACID OXALATE AND PROCESS OF MAKING SAME.

Specification of Letters Patent. i Patented Dec. 27, 1910.

Application filed September 20, 1909. Serial No. 518,556.

No Drawing.

To all whom it may concern:

Be it known that I, PAUL REHLKNDE'R, doctor of philosophy, chemist,citizen of the German. Empire, residing at Gharlottenburg, near Berlin,German Empire, have invented a new and useful Improvementin Vanadium.-\.cid Oxalate and Processes of Making the Same, of which the followingis a specification.

Toning salts in solid or tablet form have heretofore been made foruranium tonings, giving a red or brown tone, and for iron blue and irongreen tonings. Vanadium green tonings for which vanadium chlorid is usedcould not be manufactured in solid form because Vanadium chlorid, VaClis either liquid or strongly hygroscopic, as are also other knownvanadium compounds of similar constitution.

I have found that a solid substance suitable for vanadium green toningscan be produced from vanadium chlorid by subjecting the same to theaction of anhydrous oxalic acid. The hydrochloric acid which is bound inthevanadium chlorid is thereby'liberated .and a solid non-hygroscopicsubstance results oxalate, oxalic ad and red prussiate of potash.

Example: 500 grams of the liquid vanadium chlorid are mixed at a temerature of from 15 to 20 C. with 1.35 k 0 ams of anhydrous oxalic acid;the mixture 1s at first pastelike but by and by under strong developmentof hydrochloric acid gas forms a dry mass which keeps unchanged and caneasily be pressed in tablet form. Any hydrochloric acid remaining in themass should be neutralized by means of caustic lime. The exactconstitution of the resulting substance is not known but it is probablethat it is an acid vanadium oxalate, Va(C O H) It is a dry, friable,nonhygroscopic substance of gray-green color which is soluble in wateror alcohol with a blue color.

A green toning solution is made by dissolving, for instance, 3.8 gramsof the above mentioned preparation, or 20 tablets of 0.19 gram each, in1 liter of water, adding 1-1- .grams of anhydrous oxalic acid, 1 gram ofiron oxalate and 1 gram'of red prussiate of potash. A bath in thissolution gives gas light or bromid papers a green tone within three tofive minutes.

I claim as my invention: I

1. The process of manufacturing a solid preparation for vanadium greentonings which consists in subjecting vanadium chlo rid to the action ofanhydrous oxalic acid.

2. The herein described vanadium compound, suitable for vanadium greentonings, the same being the product of the action of anhydrous oxalicacid upon vanadium I chlorld, and being a dry, friable, non-hygroscopicsubstance of gray-green color which is soluble in water and in alcoholwith a blue color. c

In testimony whereof I have hereunto set my signature in the presence oftwo subscribing witnesses. n

' PAUL REHLANDER.

Witnesses:

HENRY HASPER, WOLDEMAR HAUPT.

